//键盘控制 
function keyControl() {
	if(status != 1) {
		return;
	}
	var code = event.keyCode;
	switch(code) {
		case 37:
			moveLeft();
			break;
		case 38:
			rotate();
			break;
		case 39:
			moveRight();
			break;
		case 40:
			moveDown();
			break;
	}
}